Authors may NOT be paid at all for their work, or may even pay to do it.

I am a self-funded PhD student and no one paid me for the work that went into my open access paper. As it happens in this case the journal waived the publication fee, so no one paid anyone anything except I suppose the nominal pro-rata portion of my university fees that I paid.

That is true also. The pre-pub route may be your best bet if that is a concern. One shoe does not fit all feet. I am only trying to argue the merits of the Open Access model. It is certainly not perfect.